1. Field of the Invention
The present invention relates to retardation films and also relates to polarizing plates and liquid crystal displays including retardation films.
2. Description of the Related Art
Recently, tablets and other mobile devices have been widely used which include liquid crystal displays working in an in-place-switching (IPS) mode. Examples of optical films under research for use in tablets and other mobile devices include those including an optically anisotropic layer that exploits the orientation of a liquid crystal compound. Specifically, Japanese Unexamined Patent Application Publication No. 2009-86260 discloses a retardation film including a transparent substrate, an optically anisotropic layer on one surface of the transparent substrate, and a retardation layer on the other surface of the transparent substrate (see, for example, FIG. 1 of this reference).
The needs for lower profiles on tablets and other mobile devices are increasing the demands for thinner retardation films used in IPS-mode liquid crystal displays. One known technique for fabrication of thinner retardation films is disclosed in Japanese Unexamined Patent Application Publication No. 2012-255926. Specifically, this reference discloses a retardation film including a positive C-plate and a positive A-plate or optically biaxial plate that are laminated together in direct contact without an adhesive therebetween.